Thermoformable splint structure with integrally associated oxygen activated heater and method of manufacturing same

ABSTRACT

An integrated thermoformable splint and heater and method for manufacturing same includes a thermoplastic material and an oxygen activated heater operatively associated with the thermoplastic material. The integrated thermoformable splint and heater are sealed within an oxygen impermeable housing. Oxygen is allowed to activate the heater either by removing the assembly from the sealed housing, or, by displacement of a removable seal that will allow oxygen to penetrate a porous region in the housing, and, in turn, come into contact with the heater.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/206,252 filed Mar. 12, 2014, the contents of which are fullyincorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a portable thermoformable splint structure incombination with a heater that utilizes atmospheric oxygen as a sourceof a chemical reactant for an exothermic reaction.

BACKGROUND OF THE INVENTION

Thermoformable materials have been used in association with casts andsplints for medical purposes for several years. Indeed, such materialsoffer several benefits over conventional “plaster” casts and splints,such as faster set times, eliminating the lengthy application processassociated therewith and the dampness inflicted on the patients skin.

U.S. Pat. No. 4,778,717 is directed to a specific structure for athermoplastic, thermoformable composite.

U.S. Pat. No. 5,652,053 discloses utilizing a molecular orintermolecular combination of materials comprised of aninter-penetrating polymer network so as to cause the combined structureto transfer from an amorphous state to a viscoelastic and rubbery state.While such a structure may provide some support to a user, it is noteffective when a ridged support is desired such as is typically the casewhen a splint or cast is desired.

U.S. Pat App. Nos. 20080319362 and 20120101417 both disclose athermoformable cast or splint that can be used in association with anexothermic heating reaction for causing a thermoplastic material to gofrom a relatively rigid state to a malleable state so that the materialcan be formed to a portion of a patient in need of support.Unfortunately, in order to heat the thermoplastic material in such areaction, the material is placed in a separate and distinct heating bagwhere the exothermic reaction takes place. After appropriate heating,the thermoplastic material is removed from the bag and ready for use.

In addition, the assignee of the present invention has providedoxygen-based heaters and various packages for same. See, e.g., U.S. Pat.No. 7,722,782, issued on May 25, 2010; U.S. application Ser. No.12/376,927, filed on Feb. 9, 2009; U.S. application Ser. No. 12/874,338,filed on Sep. 2, 2010; U.S. application Ser. No. 14/055,250 filed onOct. 16, 2013; U.S. application Ser. No. 14/058,719, filed on Oct. 21,2013; U.S. application Ser. No. 14/058,496, filed on Oct. 21, 2013; and,U.S. Ser. No. 13/734,594, filed Jan. 4, 2013, all of which areincorporated herein by reference.

These disclosed heaters and packages are successful at providing anoxygen based heater and/or package for same.

While the above disclosed devices and methods may be capable ofproviding effective formable splints or casts without the use of water,none of such devices disclose a single, integrated structure comprisedof a thermoplastic material for use with a splint, or the like, and anoxygen activated heater constructed in association with thethermoplastic. The present invention is provided to solve these andother problems.

SUMMARY OF THE INVENTION

The present invention is directed to an integrated thermoformable splintand heater comprising a thermoplastic material having a top side and abottom side opposite the top side and an oxygen activated heateroperatively attached in association with at least one of the top andbottom sides of the thermoplastic material.

In a preferred embodiment of the invention, the oxygen activated heaterincludes a heater sheet, a wicking layer and an air diffuser layer eachhaving a respective top surface and a bottom surface opposite theirrespective top surfaces. The bottom surface of the heater sheet ispositioned in operative contact with at least one of the top or bottomsides of the thermoplastic material, and, the bottom surface of thewicking layer is positioned in operative contact with the top surface ofthe heater sheet. In this preferred embodiment, the bottom surface ofthe diffuser layer is positioned in operative contact with the topsurface of the wicking layer. The wicking layer incorporates anddistributes an electrolyte for operative use with the heater sheet uponexposure of the heater sheet to oxygen.

In another preferred embodiment of the invention, the heater sheetcomprises a metal-based substrate that exothermically reacts with andupon exposure to oxygen.

In another preferred embodiment of the invention, the wicking layer iseliminated and the electrolyte is incorporated directly into the heatersheet.

In the preferred embodiment of the invention, at least one of the bottomsurface of the heater sheet and the associated top or bottom side of thethermoplastic material includes a binding component there between. Thebinding component may include an adhesive and/or a non-woven fabric.

It is also contemplated that the invention includes a heat insulatingmaterial associated with the bottom side of the thermoplastic material.

It is also contemplated that the invention includes a heat insulatingmaterial associated with the top side of the heater. It is alsocontemplated that the air diffuser layer can serve as the heatinsulating material on the top side of the heater sheet or wickinglayer.

In still another preferred embodiment of the invention, the air diffuserlayer includes a peripheral region around the entirety of the bottomsurface of the air diffuser layer. This peripheral region is secured toa portion of the associated top or bottom side of the thermoplasticmaterial, to, in turn, contain the heater sheet and wicking layer inoperative association with the thermoplastic material.

The preferred embodiment of the invention includes an outer housinghaving an interior region and an outer surface. In this preferredembodiment, the oxygen activated heater and the thermoplastic materialare contained within the interior region of the outer housing. The outerhousing includes a seal and is made from a material that substantiallyprecludes transfer of oxygen into the interior region of the outerhousing.

In one preferred embodiment of the invention, the outer housing includesan oxygen penetration region and a removable seal over the oxygenpenetration region. Oxygen is thus allowed to enter into the interiorregion of the outer housing, and, in turn, into contact with the oxygenactivated heater upon at least partial displacement of the removableseal.

The present invention also includes a method for manufacturing anintegrated thermoformable splint and heater comprising the steps offabricating an oxygen activated heater; attaching a thermoplasticmaterial with the oxygen activated heater; positioning the attachedthermoplastic material and oxygen activated heater within an interiorregion of a housing; and sealing the housing so as to preclude ingressof oxygen into the interior region of the housing, and, in turn,precluding activation of the oxygen activated heater.

In a preferred embodiment of the method, the step of fabricating anoxygen activated heater comprises the steps of: placing an electrolytewicking layer on a top surface of metal based heater substrate, whereinthe wicking layer includes a top surface and a bottom surface oppositethe top surface; and, positioning an air diffuser layer over theelectrolyte wicking layer so as to sandwich the electrolyte wickinglayer between the air diffuser layer and the metal based heatersubstrate.

The thermoplastic material includes a top side and a bottom sideopposite the top side. It is preferred that the method further includesthe step of adhering the metal based heater substrate to the top side ofthe thermoplastic material. It is also preferred that the outerperipheral region of the air diffuser layer is secured to a portion ofthe top side of the thermoplastic material.

In another preferred embodiment of the method, the step of adhering themetal based heater to the top side of the thermoplastic materialcomprises the step of associating an adhesive or a non-woven felt withthe top side of the thermoplastic material and a bottom surface of themetal based heater substrate.

In still another preferred embodiment, the method further includes thesteps of: forming an oxygen penetration region into the outer housingfor allowing ingress of ambient oxygen into the interior region of thehousing, and, in turn, into contact with the oxygen activated heater;and, associating a removable seal over the oxygen penetration region soas to substantially preclude the ingress of oxygen into the interiorregion of the housing until the removable seal is displaced.

The present invention is also directed to a thermoformable splint kitcomprising: a thermoplastic material having a top side and a bottom sideopposite the top side; an oxygen activated heater operatively attachedin association with at least one of the top and bottom sides of thethermoplastic material, wherein the thermoformable splint and oxygenactivated heater are sealed within an oxygen impermeable housing; and,an elastic bandage for securing the thermofomable splint to a patientafter it has been formed into a desirable configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the detailed description serve to explain the principlesof the disclosure. No attempt is made to show structural details of thedisclosure in more detail than may be necessary for a fundamentalunderstanding of the disclosure and the various ways in which it may bepracticed. In the drawings:

FIG. 1 of the drawings is an exploded view of the present invention;

FIG. 2 of the drawings is an elevated cut-away view of the presentinvention;

FIG. 3 of the drawings is a top perspective view of one of the featuresof the present invention;

FIG. 4 of the drawings is a top view of one of the features of thepresent invention; and

FIG. 5 of the drawings is an elevated side view of one of the featuresof the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The disclosure and the various features and advantageous details thereofare explained more fully with reference to the non-limiting embodimentsand examples that are described and/or illustrated in the accompanyingdrawings and detailed in the following description. It should be notedthat the features illustrated in the drawings are not drawn to scale,and features of one embodiment may be employed with other embodiments,as the skilled artisan would recognize, even if not explicitly statedherein. Descriptions of well-known components and processing techniquesmay be omitted so as to not unnecessarily obscure the embodiments of thedisclosure. The examples used herein are intended merely to facilitatean understanding of ways in which the invention may be practiced and tofurther enable those of skill in the art to practice the examples of thedisclosure. Accordingly, the examples and embodiments herein should notbe construed as limiting the scope of the invention.

Integrated thermoformable splint and heater 10 is shown in FIG. 1 ascomprising thermoplastic material 12 and oxygen activated heater 18.Thermoplastic material 12, which will result in a formable and rigidsplint, has top side 14 and bottom side 15. As would be understood tothose having ordinary skill in the art, the thermoplastic material isreadily available from numerous sources and becomes malleable(“formable”) upon heating to a predetermined temperature, such asapproximately 210 degrees F. The thermoplastic material will revert backtoward a rigid state as the temperature dissipates.

Oxygen activated heater 18 includes heater sheet 20, wicking layer 24and air diffuser layer 28. Heater sheet 20, wicking layer 24 and airdiffuser layer 28 each have a top surface and a bottom surface 21 and22, 25 and 26, and, 29 and 30, respectively. The heater sheet comprisesa metal-based substrate that exothermically reacts with and uponexposure to oxygen. Although the heater sheet is identified as a “sheet”or “substrate”, it is contemplated by the present invention that theheater sheet can actually be applied as a layer, such as by depositioncoating, rolling of material, etc.

Examples of the chemistry and general mechanical configurationsassociated with oxygen activated heaters are known in the art andspecific examples have been incorporated herein by reference in theBackground of the Invention. As will be readily understood by thosehaving ordinary skill in the art with such heaters, wicking layer 24serves to distribute the electrolyte evenly into the heater sheet. Thiselectrolyte facilitates the reaction that takes place when the heatersheet is exposed to oxygen.

As shown in greater detail in FIG. 2 (but as is also apparent in FIG.1), bottom surface 22 of heater sheet 20 is operatively associated withtop side 14 of thermoplastic material 12. Such association can occur asa result of chemical or mechanical bonding there between, or acombination thereof. For example, as shown in FIG. 1, top side ofthermoplastic material 12 is associated with binding component 34. Inthis embodiment, the binding component comprises a non-woven fabricsecured to the thermoplastic material. Although a non-woven fabric hasbeen disclosed, other binding components are also contemplated by thepresent invention, including, but not limited to, adhesive materials,such as glue and double sided thermal tape. (See, for example, doublesided thermal tape 34, shown in FIG. 3). In addition to the felt actingas a binding agent, desired felt may also include some heat insulatingproperties. Accordingly, it is contemplated that such felt, or otherheat insulating material 40 (see FIG. 5) also be associated with bottomside 15 of thermoplastic material 12 inasmuch as the bottom side will bethe side that comes into contact with the skin of a patient. Heatinsulating material 40 in FIG. 5 can serve as a resilient pad, known asa cast pad, and is placed on bottom side 15 of thermoplastic material 12for providing thermal protection while integrated thermoformable splintand heater 10 are being formed to the appropriate region of a patient,as well as providing comfort to the wearer after the thermoplasticheater reverts from a malleable state back to a rigid state.

As can be seen in FIGS. 1 and 2, bottom surface 26 of wicking layer 24is operatively associated with and over top surface 21 of the heatersheet. Additionally, bottom surface 30 of air diffuser layer 28 isoperatively positioned over top surface 25 of the wicking layer. Asshown in FIG. 2, air diffuser layer (which allows relatively uniformdispersion of oxygen toward and in contact with the wicking layer, and,in turn, the heater sheet upon association with oxygen) includesperipheral region 45 as a result of it having a length and width greaterthan the length and width of the wicking layer and heater sheet.Accordingly, peripheral region 45 of air diffuser layer 28 is adhered toa portion of the top side of thermoplastic material 12. Such adherencesecures/contains the heater sheet and wicking layer in operativeassociation with the thermoplastic material.

As shown in FIGS. 1 and 2, integrated thermoformable splint and heater10 further includes outer housing 50. The outer housing, once assembledabout oxygen activated heater 18 and thermoplastic material 12, includesinterior region 51 and outer surface 52 (see FIG. 2). As can be seen inFIG. 2, such an assembly is completely positioned within the interiorregion of the outer housing. As shown in FIGS. 1 and 2, outer housing 50includes first and second sheets of material 58, 59, respectively. Thefirst and second sheets of material are adhered at their edges (see FIG.2) so as to form seal 53. The outer housing is fabricated from amaterial that is relatively impervious to oxygen transmission. Oneexample of acceptable material for the outer housing is commerciallyavailable from Curwood Inc. P.O. Box 2968, 2200 Badger Ave., Osjkosh,Wis. 54903 under the trade name Liquiflex® A6661-MO. Seal 53 also isrelatively impervious to oxygen transmission.

Outer housing 50 may include oxygen penetration region 55 and removableseal 56 operatively positioned over and around the oxygen penetrationregion, as shown in FIG. 4. The oxygen penetration region includespores, or sections that will allow oxygen transmission into interiorregion 51 of the outer housing. However, removable seal 56 is comprisedof a material (that may be the same as the material used for outerhousing 50) that is intended to precluded oxygen transmission therethrough. Accordingly, oxygen will be precluded from entering interiorregion of the housing unless and until the removable seal is at leastpartially removed. Although outer housing has been described with anoxygen penetration region, it is also contemplated that such a regionnot be used. In such a case, oxygen will only be transmitted to theoxygen activated heater upon physical removal of the integrated heaterand thermoplastic material from interior region 51 of the outer housing.

Integrated thermoformable splint and heater 10 is manufactured byfabricating oxygen activated heater 18 with air diffuser layer 28,wicking layer 24 and a metal-based (such as zinc) heater substrate 20,and securing all of them to thermoplastic material 12. As previouslyexplained, the heater sheet is adhered to the thermoplastic material bymeans of a chemical and/or mechanical bond, such as with non-woven feltor an adhesive applied to top side 14 of the thermoplastic material. Inaddition, cast pad 40 (FIG. 5) may be applied to bottom side 15 of thethermoplastic material for thermal protection and comfort. As alsopreviously explained, the air diffuser layer includes a peripheralregion 45 that extends beyond the peripheries of the wicking layer andheating sheet. Inasmuch as the thermoplastic material has a length andwidth that is also greater than that of the wicking layer and heatingsheet, the peripheral region 45 of the air diffuser layer can be securedto a portion of the thermoplastic material (see FIG. 2). In thisinstance, the heater sheet is held against the thermoplastic material bybeing “sandwiched” between the air diffuser and the thermoplasticmaterial, and direct binding of the heater sheet to the thermoplasticmaterial may not be required.

An outer housing 50 is fabricated from a flexible material that isrelatively impermeable to oxygen. The outer housing is constructed tohave a top sheet 58 and bottom sheet 59. Once constructed, the combinedand integrated oxygen activated heater 18 (FIG. 1) and thermoplasticmaterial 12 are positioned within what will become interior region 51(FIG. 2) of the outer housing. The top and bottom sheet of the outerhousing are then sealed together, optionally under a vacuum, formingseal 53 so that the interior region of the outer housing issubstantially devoid of oxygen, and wherein the outer housingsubstantially conforms around the thermoplastic material and oxygenactivated heater.

As an alternative embodiment, top sheet 58 of the outer housing can befabricated with pores, or oxygen penetration regions 55, and a removableseal 56 positioned there over. As previously described, in such anembodiment, oxygen will only transmit into the interior region of theouter housing upon at least partial removal of the removable seal.

In operation, a desired user of the integrated thermoformable splint andheater would merely open the outer housing (by, for example, cutting asealed edge with a scissors, or by tearing at a perforated line) andthen removing the integrated thermoplastic material and oxygen activatedheater there from. As oxygen from the ambient environment comes intocontact with the air diffuser layer, and, in turn, into contact with thewicking layer, a chemical reaction will occur causing the heater sheetto create an exothermic reaction. This exothermic reaction will resultin the release of heat from the heater sheet toward and into thethermoplastic material. Once the temperature is high enough, it willcause the thermoplastic material to deform, or become malleable. At thattime, a person would then place the integrated device onto a person'sarm (for example) and press the thermoplastic material against theperson's arm until it forms thereto. Once properly formed, an elasticbandage, or the like, is wrapped around the person's arm and theintegrated thermoplastic material and oxygen activated heater so as tosecure it in place. Inasmuch as the side of the thermoplastic materialapplied to the person's arm includes an insulating pad (such as a castpad) he or she will not be subjected to unsafe temperatures. The airdiffuser layer also has heat insulating properties, so the personapplying the device will also be protected from unsafe temperatures.

Shortly after the thermoplastic material has been properly formed, theexothermic reaction from the heater will cease and the elevatedtemperature of the thermoplastic material will quickly begin todissipate. Such dissipation of heat will then cause the thermoplasticmaterial to revert from a malleable (moldable) state, back toward arigid state.

The integrated thermoformable splint and integrated heater is alsofabricated as a kit. The kit includes the integrated thermoplasticmaterial and oxygen activated heater associated securely positionedwithin the outer housing, and an elastic bandage.

Additional features, advantages, and embodiments of the invention may beset forth or apparent from consideration of the detailed description anddrawings. Moreover, it is to be understood that the foregoing summary ofthe invention and the associated detailed description and drawings areexemplary and intended to provide further explanation without limitingthe scope of the invention as claimed.

What is claimed is:
 1. A thermoformable member comprising: a rigidthermoplastic material having a top side and a bottom side opposite thetop side, the thermoplastic material becoming malleable above apredetermined temperature and returning to a rigid state as thetemperature dissipates; and an oxygen activated heater operativelyattached in association with at least one of the top side or the bottomside of the thermoplastic material, the oxygen activated heater heatingthe thermoplastic material to a temperature at least matching thepredetermined temperature when activated.
 2. The invention according toclaim 1 wherein the oxygen activated heater comprises: a heater sheet,an optional wicking layer and an air diffuser layer each having arespective top surface and a bottom surface opposite their respectivetop surfaces, wherein: the bottom surface of the heater sheet ispositioned in operative contact with at least one of the top side or thebottom side of the thermoplastic material; the bottom surface of thewicking layer is positioned in operative contact with the top surface ofthe heater sheet; and the bottom surface of the air diffuser layer ispositioned in operative contact with the top surface of the wickinglayer.
 3. The invention according to claim 2, wherein at least one ofthe bottom surface of the heater sheet and the associated top or bottomside of the thermoplastic material includes a binding componenttherebetween.
 4. The invention according to claim 3, wherein the bindingcomponent comprises a non-woven material.
 5. The invention according toclaim 3, wherein the binding component includes an adhesive.
 6. Theinvention according to claim 2, wherein the heater sheet comprises ametal-based substrate that exothermically reacts with and upon exposureto oxygen.
 7. The invention according to claim 2, wherein the wickinglayer has been dosed with an electrolyte for operative use with theheater sheet upon exposure of the heater sheet to oxygen.
 8. Theinvention according to claim 1, further including a heat insulatingmaterial associated with at least one of the top side or the bottom sideof the thermoplastic material.
 9. The invention according to claim 8,wherein the heat insulating material comprises at least one of the airdiffuser layer and a heat insulating pad.
 10. The invention according toclaim 1, wherein the thermoplastic material is a splint.
 11. A methodfor manufacturing a thermoformable member comprising the steps of:fabricating an oxygen activated heater; physically associating athermoplastic material with the oxygen activated heater; positioning theattached thermoplastic material and oxygen activated heater within aninterior region of a housing; and sealing the housing so as to precludeingress of oxygen into the interior region of the housing, and, in turn,precluding activation of the oxygen activated heater.
 12. The methodaccording to claim 11, wherein the step of fabricating an oxygenactivated heater comprises the steps of: placing an electrolyte wickinglayer on a top surface of a metal based heater substrate, wherein thewicking layer includes a top surface and a bottom surface opposite thetop surface; and positioning an air diffuser layer over the electrolytewicking layer so as to sandwich the electrolyte wicking layer betweenthe air diffusing layer and the metal based heater substrate.
 13. Themethod according to claim 12, further comprises the step of securing anouter peripheral region of the air diffuser layer to a portion of a topside of the thermoplastic material.
 14. The method according to claim13, wherein the step of adhering the metal based heater to the top sideof the thermoplastic material comprises the step of associating at leastone of an adhesive and a non-woven felt with the top side of thethermoplastic material and a bottom surface of the metal based heatersubstrate.
 15. The method according to claim 11, further including thesteps of: forming an oxygen penetration region into the outer housingfor allowing ingress of ambient oxygen into the interior region of thehousing, and, in turn, into contact with the oxygen activated heater;and associating a removable seal over the oxygen penetration region soas to substantially preclude the ingress of oxygen into the interiorregion of the housing until the removable seal is displaced.
 16. Athermoformable member comprising: a thermoplastic material having a topside and a bottom side opposite the top side; an oxygen activated heateroperatively attached in association with at least one of the top side orthe bottom side of the thermoplastic material; and an outer housinghaving an interior region and an outer surface, wherein the oxygenactivated heater and the thermoplastic material are contained within theinterior region of the outer housing.
 17. The invention according toclaim 16, wherein the outer housing includes a seal and wherein theouter housing comprises a material that substantially precludes transferof oxygen into the interior region of the outer housing.
 18. Theinvention according to claim 17, wherein the outer housing includes anoxygen penetration region and a removable seal over the oxygenpenetration region, wherein oxygen enters into the interior region ofthe outer housing, and, in turn, into contact with the oxygen activatedheater upon at least partial displacement of the removable seal.